Topological Lifshitz transition-induced bipolarity of anomalous Nernst effect in kagome magnet YCo3

Abstract

The kagome lattice, renowned for hosting topological band structures and rich magnetic behaviors, offers an exceptional setting to investigate unconventional transport in magnetic topological systems. Controlling the polarity of the anomalous Nernst effect (ANE) is crucial for designing flexible thermoelectric devices, such as thermopiles, where the ability to switch the thermoelectric voltage sign can dramatically enhance energy conversion efficiency and output. Here, we demonstrate such a bipolar ANE in the kagome magnet YCo3, driven by a temperature-induced topological Lifshitz transition. With a Curie temperature TC~225 K, sizable anomalous Hall and Nernst effects emerge below TC. Supported by the first-principles calculations, the AHE and ANE are suggested to be dominated by the intrinsic mechanism. Furthermore, the intrinsic anomalous Hall conductivity exhibits a piecewise-linear dependence on magnetization, with an abrupt slope change near 100 K, consistent with the Karplus-Luttinger mechanism. Concurrently, the anomalous Nernst coefficient SAyx reverses its sign around the same temperature, realizing the crucial bipolarity. These anomalies could be interpreted as a topological Lifshitz transition, enabled by the evolution of Co moments that could shift the Fermi level relative to Weyl nodes. Our work reveals YCo3 as a prototypical kagome magnet where temperature and magnetism directly govern both Weyl node topology and the bipolar ANE, opening a pathway to magnetically control thermoelectric output in topological quantum materials.

arXiv comment16 pages, 7 figures,

References in corpus (27)

• Electronic Structure of Pyrochlore Iridates: From Topological Dirac Metal to Mott Insulator
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Dirac semimetal and topological phase transitions in A3Bi (A=Na, K, Rb)
• Topological nodal semimetals
• Topological quantum chemistry
• Giant anomalous Hall effect in a ferromagnetic Kagome-lattice semimetal
• Massive Dirac fermions in a ferromagnetic kagome metal
• Large anomalous Nernst effect at room temperature in a chiral antiferromagnet
• Trajectory of Anomalous Hall Effect toward the Quantized State in a Ferromagnetic Topological Insulator
• Large intrinsic anomalous Hall effect in half-metallic ferromagnet Co3Sn2S2 with magnetic Weyl fermions
• Evidence for Magnetic Weyl Fermions in a Correlated Metal
• Giant anomalous Nernst effect and quantum-critical scaling in a ferromagnetic semimetal
• Discovery of a quantum limit Chern magnet TbMn6Sn6
• Intrinsic vs. extrinsic anomalous Hall effect in ferromagnets
• High-throughput calculations of magnetic topological materials
• Zero-field Nernst effect in a ferromagnetic kagome-lattice Weyl-semimetal Co3Sn2S2
• Anomalous Nernst effect beyond the magnetization scaling relation in the ferromagnetic Heusler compound Co${}_2$MnGa
• Anomalous Nernst and Righi-Leduc effects in Mn${}_3$Sn: Berry curvature and entropy flow
• Magnetic Topological Quantum Chemistry
• Linear magnetization dependence of the intrinsic anomalous Hall effect
• Anomalous transport due to Weyl fermions in the chiral antiferromagnets Mn${}_3$$X$, $X$ = Sn, Ge
• Berry curvature unravelled by the Nernst effect in Mn${}_3$Ge
• Thermoelectrics: from Longitudinal to Transverse
• Intrinsic anomalous Nernst effect amplified by disorder in a half-metallic semimetal
• Exchange-biased topological transverse thermoelectric effects in a Kagome ferrimagnet
• Pressure-tunable large anomalous Hall effect of the ferromagnetic kagome-lattice Weyl semimetal Co3Sn2S2
• Angle-dependent magnetoresistance and its implications for Lifshitz transition in W2As3